Threads

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Threading
{
    class Program
    {
          private static Mutex mutex = new Mutex();
          private static int Sum = 0;

            static void Main(string[] args)
            {

                Thread[] _workers = new Thread[1000];

                for (int i = 0; i < _workers.Length; i++)
                {
                    _workers[i] = new Thread(new ParameterizedThreadStart(MutexDemo));
                    _workers[i].Name = string.Format("Thread {0} :", i + 1);
                    _workers[i].Start(i);
                }

                foreach (Thread thread in _workers)
                {
                    thread.Join();

                }
                Console.WriteLine(Sum);
                Console.ReadKey();
            }

            static void MutexDemo(object custom)
            {
                try
                {
                   mutex.WaitOne();

                    int i = (int)custom;

                    Console.WriteLine("{0} вошел в метод",
                        Thread.CurrentThread.Name);
                    Console.WriteLine("Сумма до - {0}, i = {1}",Sum,i);
                    if (i%2 == 0)
                    {
                        Sum = Sum + i * 10;
                    }
                    else
                    {
                        Sum = Sum - i * 10;
                    }

                    Thread.Sleep((new Random().Next(1,100)));
                    Console.WriteLine("Сумма после - {0}, i = {1}", Sum, i);
                    Console.WriteLine("{0} вышел из метода",
                        Thread.CurrentThread.Name);

                }
                finally
                {
                    mutex.ReleaseMutex();
                }
            }
        }

}